This invention relates to a known type of blank feeder, such as the M.I. "UNIFEEDER" made by Multifold-International, Inc., 750 Main Street, Milford, Ohio, 45150, or similar feeders made by others in the trade.
Such blank feeders are designed to maintain the blank hoppers of folder-gluers filled to a uniform height, on demand, thereby avoiding misfeeds, or non-feeds, due to overweight of blanks on the bottom feed mechanism of the hopper.
The blank magazine of the "Unifeeder" type device can be filled with a relatively high stack of flat blanks. The nodule surfaced conveyor belt advances under the open bottom of the magazine to urge the lower most blanks through a passage, or gateway, in the lower front wall, formed by the curved lower ends, of a set of vertical smooth bars, as the upper, immovable element, and by the upper stretch of the conveyor, as the lower, movable element.
The passage, or gateway, between the said elements is of predetermined height, capable of passing several thickness of blank at a time, so that the blanks may advance in shingled formation, along a path, with predetermined spacing, on the feed belt, until they are deposited in the hopper of the folder-gluer.
A constant uniform feed has been the objective of such feeders with no down time from jams, doubles, skips, surges or scuffing.
However, the fixed, vertical bars forming the immovable, curved, upper element of the blank passage, gateway or nip seems to have been a major cause of any such loss of production as may have occurred in machines of this type.